In today's digital world, digital imaging devices, such as digital cameras, are enjoying great success. While digital imaging devices may provide superior image quality and versatility to the user, the rate with which an image is acquired in these devices is often slow. This is usually due to image processing operations performed by the device prior to storing the image on a storage medium.
More particularly, in digital imaging devices, an image is captured by an image sensor and the raw image data is supplied to a central processing unit (CPU) for processing. The processing usually includes conventional image processing and compression of the image data. The processed image data is then stored onto a storage medium. A significant period of time is often required to perform the image processing. More particularly, each part of the image processing pipeline is usually performed sequentially on the entire image. The processed image data is then stored onto a storage medium. Writing the image data for the entire image is also a time-consuming process, often much greater than the image processing. In addition, many digital imaging devices are unusable during the time from when the image is obtained by an image sensor until it is stored on the storage medium. Therefore, digital imaging devices do not efficiently support the rapid capture of a series of images.
In an effort to address this problem, digital imaging devices have been developed that delay image processing until some time after the raw image data has been stored. More particularly, these devices include a storage medium that is usually large enough to store the raw data for up to 10 images. The raw image data is stored on the storage medium, and the CPU processes the raw data at a later time. However, this approach continues to suffer from the disadvantage of limited ability to support the rapid capture of a series of images, and suffers from the additional disadvantage of requiring a large amount of memory.
Other devices buffer images that have already been processed, which also requires a large amount of memory. In addition, this technique suffers from the problem of risking picture loss as the imaging device reports “ready” before the image has been completely written to the permanent storage device.
Therefore, there is a need for a method and apparatus that provides for decreased image acquisition time in digital imaging devices. More particularly, there is a need for a method and apparatus that enables a digital imaging device to capture multiple images rapidly by decreasing the time period between capturing a first image and being prepared to capture another image.